Optical properties of thin films and the Berreman effect

Harbecke, B.; Heinz, Bernd; Große, Peter

doi:10.1007/bf00616061

Cited by 195 publications

(142 citation statements)

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“…refs. [74][75][76] vibrations have either zero net vibrational dipole moment or it is parallel to the surface (TO modes). However, the "LO" symmetric Si-O-Si vibrations again differ from that of bulk silica materials or thicker films because no long-range electric field induced by this vibration is possible in the monolayer silica film.…”

Section: Vibrational Spectroscopy: Experiments Vs Theorymentioning

confidence: 99%

On the geometrical and electronic structure of an ultra-thin crystalline silica film grown on Mo(112)

et al. 2007

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Abstract. The atomic structure of a well-ordered silica film grown on a Mo(112) single crystal substrate is discussed in detail using the experimental and theoretical results available to date. New photoelectron spectroscopy results using synchrotron radiation and ultraviolet spectroscopy data are presented. The analysis unambiguously shows that the ultra-thin silica film consists of a two-dimensional network of corner sharing [SiO 4 ] tetrahedra chemisorbed on the unreconstructed Mo(112) surface. The review also highlights the important role of theoretical calculations in the determination of the atomic structure of the silica films and in interpretation of experimental data.

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Section: Vibrational Spectroscopy: Experiments Vs Theorymentioning

confidence: 99%

On the geometrical and electronic structure of an ultra-thin crystalline silica film grown on Mo(112)

et al. 2007

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“…26,27 The phenomenon that the equivalent of longitudinal optical modes in an infinite medium can be stimulated in thin films by P-polarized IR radiation under oblique incidence is known as the Berreman effect. ͑top panels͒ and 3600 to 3900 cm Ϫ1 ͑bottom panels͒ which have been collected at 300 K during the film deposition ͓left panel ͑1-4͔͒ and the annealing process ͓right panel ͑5-8͔͒.…”

Section: The Vibrational Excitations Of the System Sio 2 õMo"112…mentioning

confidence: 99%

Morphological and electronic properties of ultrathin crystalline silica epilayers on a Mo(112) substrate

et al. 2002

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Ultrathin crystalline silica layers grown on a Mo͑112͒ substrate have been shown to be a useful silica model oxide support in surface science model catalyst studies. As the oxide support material plays an important role in the catalytic process, a multitechnique surface science study is presented to characterize the morphological and electronic properties of the heteroepitaxial system SiO 2 /Mo(112). The long-range order of the silica epilayer which grows commensurate with a c(2ϫ2) surface unit mesh on the Mo͑112͒ substrate is studied by low-energy electron diffraction ͑LEED͒. The defect structure of the silica epilayer is characterized in a spot profile analysis ͑SPA͒-LEED study. Antiphase domain boundaries split the silica epilayer into an array of silica crystal grains whose average size and shape is determined. Aiming to prepare flat silica surfaces, the change in the surface roughness with progress in the film preparation is monitored in a combined SPA-LEED and scanning tunneling microscopy ͑STM͒ study and seen to influence also the Si-O stretching frequency in the infrared-reflection-absorption spectroscopy spectra. In STM images of the final silica film an average surface roughness of about 1 Å is detected. It is possible to visualize the silica film unit cell periodicity. A combined anger electron spectroscopy and ultraviolet photoelectron spectroscopy valence band study confirms the silica film stoichiometry and the growth of a 4:2 coordinated silica polymorph on the Mo͑112͒ surface. These various surface science studies allow us to propose models for the growth and structure of the silica epilayer on the Mo͑112͒ surface.

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“…For excitation conditions close to the dispersion of such eigenmodes, these structures can exhibit peculiar properties. A representative example is the Berreman absorption feature observed for p-polarized light illuminating dielectric thin films backed by a metal substrate [5][6][7]. This resonant absorption, close to the longitudinal phonon frequency, was recently attributed to the excitation of the so-called "Berreman mode" [8].…”

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confidence: 99%